Method and apparatus for heattreating textile fabrics



m w 1 P 1 mm m E. I I V y 2 m N .3 1.. m R w m 2 H H. E. PECK METHOD ANDAPPARATUS FOR HEAT-TREATING TEXTILE FABRICS Feb. 24, 1953 Filed Oct. 27,1949 H. E. PECK Feb. 24, 1953 METHOD AND APPARATUS FOR HEAT-TREATINGTEXTILE FABRICS Filed Oct. 27, 1949 3 Sheets-Sheet 2 INVENTOR. HENRY E.PEGK Patented Feb. 24, 1953 METHOD AND APPARATUS FOR HEAT- TREATINGTEXTILE FABRICS Henry-E.Peck, Fairport, N. Y., assignor, by mesneassignments, to Palatine Dyeing Company, Inc., St. J ohnsville, N. Y., acorporation of New York Application October 27, 1949, Serial Nor-123,925

8 Claims.

The present invention relates to a method and apparatus forheat-treating textile fabrics: and more particularly to amethodandapparatus for heat-treating thermoplastic fabrics, such as nylon, tobring about the physical changes required to give thefabric adimensional. stability or set, and to give the fabric such otherdesirable physical characteristics 4 as will resultffrom properheat-treating.

So far as I know theconventional method of heatetreating/ or settingnylon" is to wind the fabric loosely on acore or'roll and to place thecore or roll in-anautoclave t'o which steam at 5 lbs; to 25 lbs. persquare inch pressure isadmitted'. The material i'sheld in this steam atmosphere for a period of a few minutes to half an hour; This method ofheat-treating the fabric produces satisfactory "results but is slowbecause only one batch of the fabric can be heated at a time; it is'notcontinuous.

Eiforts'have beenmade, therefore, to develop a process and a machine forcontinuously heattreating" or' setting nylon and similar fabrics.According to one idea, the fabric isimade to make a 180 Wrap arounda-rolL-which is run at the speed of traveler the'fabric, andwhich. isheated by a liquid or vapor mediuminsidexthe roll. The temperature iscontrolled by a potentiometer controller" actuated. by a thermocouple inthe roll surface. Difficulties have been; experienced, however, incontrolling theheat' in this machine; and; moreover, this machine hasthe disadvantage that the" material cannot be stretched ortensionedcrosswise as itxmoves overthe roll.

Another idea involves running: the fabric through an ovenon a pin"tente'r-fra'me conveyor. A fuel gas burner isfired directly intoxtheupper chamber of thisoven'; and the products of combustion combined withair are blown by means of fans down onto the fabric asit'iscarrled onthe tenter-frame conveyor through the oven. Again, however, difficultyhas been experienced in controlling the heat. Stratification of hightemperature streaks in the atmosphere of the oven isb'ound to takeplaceinspite of the mixing action-of the fans. Since it isnecessary, inorder to effect setting, to bring the fabric. temperature up toa-temperature close to that at which it may be damaged by oxidation ormelting, this lack'of temperature uniformity is very detrimental. Theentire oven. temperature. must be held below the temperature at whichnylon melts so that if it becomes necessary to stop the fabricin'thezoven' it will not burn up. How.- ever, when theoven-temperatureis held atthis 2. level, a relatively; long; period ofexposure is required to bring the fabric up close to this level wlththeresult that-the-fabric is-exposedrto-high temperature for so long thatoxidation; evident by yellowing, begins. to occur.

The primary object of the present invention is to provide a method andmachine for heattreating fabrics in which the fabric can. be treatedcontinuously .and'brought up rapidly to the; desired. temperature.without danger of burning.

Another objectof the invention is to provide a method and machine forheat-treatingfabrics in which the fabric is heated by radiant heatapplied over a large area and at such a relatively low temperature thatburning. will be prevented.

Another. object of the invention is to provide a machine forheat-treating nylonand similar fabricsin which the fabric will beprotected from burning, even if the mechanism for conveying the fabricthrough the heat-chamber-is stopped for any reason.

Further objects of the invention are to providea machine forheat-treating. fabricswhich will be simplein construction and which maybe operated at a relatively low cost.

Other obj ects-of the invention will. be apparent hereinafter from thespecification and from the recital of the appended claims.

In the process and machine-of the present in vention, the fabric iscarried by a standard .pin tenter frame conveyor through aheating chamber while heat is transmitted to thefabric by direct radiation. Insteadof using. infra-red lamps or thelike for heating the fabric, -however, Iemploy heated...metal. plates, which are located parallel to the fabricand positioned a few inches above and below it. The metalplates may beheated by disc heaters or in any other suitable: manner. plates mayrange from 600 to 900 F. for nylon. Otherv temperatures may be employedforother materials but insuch range that the peak of the radiationemission at the. temperatures employed substantially coincides with thehighest absorption wave-length band for the material being treated.

One result of this relatively low temperature heat source is that therate of heat transfer drops off rapidly as the fabric approaches thetemperature of the plates. This is becausethe rate of transfer of:radiant heat is proportional to the difference :in the fourth power ofthe: absolute temperatures. The rapid diminution of. heat transfer; asthe desired. temperature an- Thetemperature level of the preached,provides a self-regulating effect which greatly diminishes the harmfuleffects of irregularity in temperature. Another benefit of use oflow-temperature plates is that heat distribution is more or lessindependent of the distance from the heat source to the fabric, insteadof being proportional to the square of the distance, as in the case ofheat lamps, so that uniform distribution of temperature is easilyachieved. Since the fabric is held by the tenter-frame conveyor undertension in all directions, with the method and machine of the presentinvention, then, the desired set can be achieved easily without dangerof harming the fabric.

In the drawings:

Fig. 1 a transverse sectional view taken through the heat chamber of amachine built according to one embodiment of the invention;

Fig. 2 is a view at right angles to the section of Fig. 1, parts beingbroken away to show a partial longitudinal sectional view through theheating chamber;

Fig. 3 is a fragmentary longitudinal sectional view on a greatlyenlarged scale;

Fig. 4 is a plan view of the heating chamber and adjacent parts of themachine, part of the upper heating plates, and upper curtain rods beingbroken away to show the fabric and tenterframe conveyor, and part of thefabric and conveyor being broken away to show the lower plates and lowercurtain and rods;

Fig. 5 is a fragmentary longitudinal sectional view, similar to Fig, 3,but showing the curtains drawn over the heating plates;

Fig. 6 is a fragmentary detail view showing the drive to the curtainrollers;

Fig. 7 is an electrical diagram showing the interlock between the mainmotor of the machine and the curtain-actuating mechanism; and

Fig. 8 is a fragmentary electrical diagram showing the controls forcertain of the heaters and the connections between these controls andthe heaters.

Referring now to the drawings by numerals of reference, In denotes aconventional tenterframe conveyor comprising two parallel endless chainswhose links are provided with tenter pins or hooks II. The chains areadapted to travel in channels l2 (Fig. 1) which are supported by railsl3 that may be secured in any suitable manner to the frame of themachine. The frame is supported by legs or uprights [6.

The nylon or other fabric F, which is to be heat-treated, is fastened tothe hooks of the tenter frame so that it may be stretched bothtransversely and lengthwise to the desired degree by the tenter framewhich is shown only fragmentarily in the drawings.

Between the ends of the machine there is provided a heating chamber 20.This comprises the upper and lower walls 2| and 22, a side wall 23, anda door 24 which closes the side of the chamber opposite to side wall 23.These constitute an outer jacket. Each of the walls 2|, 22 and 23 andthe door 24 is lined with suitable insulating material 25. The door 24and its lining is hinged at 26 to the chamber. The chamber itself issupported by the longitudinal beams '29 of the machine.

Secured to the upper wall of the heating chamber are a plurality ofidentical, inverted U-shaped channel members 30. The depending legs ofthese channel members have inturned flanges 3| (Fig. 3) at their lowerends. The flanges 3| of each channel member provide rests and guides 4for a heating plate 32 to the back of which is secured a plurality ofstandard disc heaters 34.

Secured to the lower wall 22 of the heating chamber are plurality ofother identical U-shaped channel members 30, which may be identical tothe channel members 30, but which are mounted in the reverse relation tothe channel members 30, that is, with their open ends at the top. Thesechannel members are provided with inturned flanges 3| on which rest thelower heating plates 32. To the back of each of these plates is securedalso, a plurality of standard heating discs 34.

Each plate 32 or 32' is adapted to be slid into and out of a channelmember through the door 24 of the chamber. To this end, each channelmember is open at one end, as shown at the left in Fig. 1, and beveledoff as denoted at 36 so that the plates 32 or 32 can easily be slid intoor out of it.

The upper plates 32 are disposed to be spaced a few inches above thefabric traveling through the heating chamber and the lower plates aredisposed to be spaced a few inches below the material. The disc heaters34 heat the plates by conduction and the plates transfer their heat tothe material by radiation. The several plates 32 and 32' providerelatively large heating areas above and below the fabric being conveyedthrough the heating chamber. The plates are heated by the heaters 34 toa temperature preferably between 600 and 900 F., as already stated.Because of the large area of the plates, the heat is transmitted evenlyto the fabric as it travels between the plates; and because of the lowtemperature of the plates the rate of heat transfer drops off rapidly asthe fabric approaches the temperature of the plates. This is because therate of transfer of radiant heat is proportional to the difference inthe fourth power of the absolute temperature. These two factors protectthe fabric against burning in normal operation.

It sometimes happens, however, that a breakdown occurs or that themachine must be shut down with fabric between the upper and lowerplates. To protect the fabric in the heating chamber during shut-down,two curtains 46, 46 (Figs. 2, 4 and 5) are provided that are made ofvery thin brass, aluminum or a similar reflecting metallic material.These curtains are adapted to be drawn between the upper and lowerheating plates and the upper and lower sides, respectively, of thefabric. They are normally wound on the rolls 49 and 4| which are securedto shafts 44 and 45, respectively, that are journaled in brackets 42 and43, respectively, that are secured to the frontend wall 21 of theheating chamber. A pair of parallel cables 41 connect the upper curtain46 with rolls 48 that are secured adjacent opposite ends of a shaft 49that is suitably journaled in brackets 52 (Fig. 4) that are secured tothe side wall 28 of the heating chamber. A pair of similar parallelcables ll are connected at one end to the lower curtain 46 and at theiropposite end to rollers 48 to wraparound said rollers. Rollers 4-8 aresecure adjacent opposite ends of a shaft 50 which is journaled inbrackets 52 also secured to side wall 28 of the heating chamber. Shafts44, 45, 49 and 50 are parallel.

The curtains are normally rolled up on rollers 40 and t! but may beunrolled by actuation of a piston 55 (Fig. 7) that is reciprocable in acylinder 56 (Figs. 2 and '7) which is suitably mounted on the frame ofthe machine. There egczegree is a piston rodt'l secured to the pistonwhich is connected to a rack 58-. This rack meshes with a spur pinion59. This pinion is secured to a stub shaft 34 to which is fastened spurgear 69. This gear meshes with a pinion Iil' which is secured to shaft56. There is also a spur gear 52 secured to this shaft. The spur gear 62meshes with a spur gear 63 on shaft 49. When the piston 55 is moved inone direction, therefore, the curtains are drawn and when it is moved inthe other direction the curtains are rolled up.

The direction of movement of the piston 55 is controlled by areciprocable valve 65 (Fig. 7) which reciprocates in a valve head 65. Inthe position shown in Fig. 7 compressed air is supplied from the duct 61through the duct 98 to the left hand end of the cylinder 56, and air isexhausted from the right hand end of the cylinder 56 through the duct 69and the exhaust duct I9. The numeral l9 denotes a second exhaust ductleading from the valve chamber. Compressed air may be supplied to duct61 from a main line in the shop or from any other suitable source. Thevalve 65 is spring pressed in one direction by coil spring II and isadapted to be moved in the opposite direction by energizing the coil '52to which the valve stem 65 is connected by any suitable connection 95".

The machine may be wired as illustrated diagrammatically in Fig. 'l toinsure shifting of the valve 65 and drawing of the curtains should themain motor of the machine stop for any reason.

l5 denotes the starter coil of the main motor, that is, the motor whichdrives the tenter frame. The numeral 76 denotes the start button; and Elis the stop button for this motor. The numeral I3 denotes the hold-inswitch for the holdin circuit to the motor when the start button isreleased. L1 and L2 are the main lines. When the start button is pushedin, a circuit is made from the main line L1 through line 99, startbutton It, line BI, normally-closed stop button TI, line 82, startercoil "I5, and line 83 to main line L2. Ihis starts the motor. Thecircuit to the motor is maintained after starting through a conventionalcontroller which comprises the hold-in contact '58 that bridges thelines 84 and 85. When the start button I9 is closed, a circuit is alsomade from the main line L1 through line 89, button T6, line 8i, button11, line 98, normally-closed switch 95, coil I2, and line 99 to mainline L2. This energizes coil '52 to hold the valve 95 in the positionshown in Fig. 7 with the curtains rolled up. If for any reason the mainmotor stops, the circuit to coil i2 is broken; and the spring II shiftsthe valve 69, causing the curtains to be unwound and disposed in frontof the heating plates.

When the main motor is stopped, the curtains can be drawn by pushing inbutton I99. This establishes a circuit from main line L1, through lineN13,. button I99, line I94, normally-closed stop button I92, line I95,normally-closed switch 9| and coil 92 to main line L2. This causes coil92 to be energized, opening normally-closed switch 95 and closingnormally-open switches 93 and 94. This establishes a circuit from mainline L1 through line 99, now-closed switch 94, line 91, coil 12 and line99 to main line L2, energizing coil '52 and causing the curtains to berolled up. The switch 93 operates, when closed, tomaintain this circuit.This circuit maybe broken by pushing stop button I02.

If the main motor is started with the curtains drawn, the circuit tocoil 1-2 is-broken, deener' gizing coil 72 and permitting spring II toshift valve to the right from the position shown in Fig. '7 so that thecurtains are rolled up. This happens because on starting of the mainmotor, coil 31 is energized from main line. L1 through start button 16,line BI, stop button T5, line 89, coil 81, and the line 99 to main lineL2. Energizing of coil 31 causes normally-closed switch 9I- to beopened, breaking the circuit to coil 92 allowing switches 93 and 94 toopenand switch 95 to close. Opening of switch 94 opens the circuit tocoil I2. Therefore, the curtains are rolled up.

Tension on the curtains'is provided all times by cables I49 which arewrapped around rollers MI and I42 and'whose ends are secured to acoilspring I44 (Fig. 4)..

To achieve uniform setting of the fabric out to its edges, it has beenfound that higher temperatures should be provided atthe sides of thefabric than in the center of the fabric. The higher temperature at theedges of the fabric can be achieved in various ways. For instance, theheaters 34 which are close to the edges of the tenter-frame conveyor maybe constructed to have greater wattage than the other heaters, or all ofthe heaters may be wired to provide multiple stages of heat and those,which lie above and below the edges of' the fabric may be set to maximumtemperature while the others are adjusted to a lower temperature.

As illustrated, thereare ten plates 32 in the upper portion and tenplates 32 in the lower portion of the heating chamber; and seventeen oreighteen heaters secured to each plate.

Fig. 8 shows one way in which the heatersmay be wired so that they maybe manually controlled. The numeral H0 denotes a manuallyoperateddouble-bladed switch controlling lines III and H2, which lead to theupper and lower rows of heaters, respectively. The main lines aredesignated L1 and L2. The numerals I I4 and I I5 denotesingle-bladedswitches for controlling, respectively, different heaters in aparticular row of heaters, that is, different heaters attached to asingle'plate 32 or 32. The switch H4 controls th heaters in the centerof the row or plate; the switch H5 controls the heaters at the edges ofthe row. When the switch H9 is pressed in and the switch H5, whichcontrols the heating discs 34 at the sides of the row, is closed, acircuit is made from the main line L1 through the line H6, thedouble-bladed switch H9, line III, line I I1, two outside heating discs34 ofan upper plate 32, the line H8, line H9, line I20, the'blade I2I ofswitch H5, the line I22 to the main line L2; Simultaneously a circuit ismade from the line H2, through the line I25, two outside discs 34 oftheopposed lower plate 32', line I26, to the line I29. Likewise, whenthe switch I I4 is closed, circuits are made from the main line L1through the line II6 switch H0, line III, line I30, central heating disc34, line I3I, line I32, switch blade I33, and line I34 to the main lineL2, and simultaneously-from the line I32 through the opposed lower disc34, line I31, and line H2, push button HI) and line H6 to the main lineL1.

This diagram illustrates how three discs in the same row or plate areinterconnected for control. Obviously the discs of other rows or platescan be similarly wired.

If desired, thermostatic control switchesm'ay beused tor-control thetemperatures "or the van-'- ous rows of heaters, once the rows have beenconnected to the source of electrical energy by the manually-operatedstart buttons ill), I I4 and H5, the thermostatic control switches beinginterposed in the lines to the heaters. The thermostatic switches theninsure maintenance of the desired temperatures at the heaters.

For fabrics of different widths, different numbers of heaters will beused on each plate. For a narrower fabric, for instance, not all theheaters of a row or plate need be employed. For different types offabrics, various numbers of heating plates will be used. One fabric maybe heattreated faster than another and so only part of the plates in theheat chamber need be heated for the fabric which is subject to fasterheattreatment.

The temperature of upper and lower heating surfaces can be varied byvarying the numbers of heaters turned on. Moreover, the position of thecurtain can be changed so that by drawing it part way into place,certain of the plates 32 and 32' may be shielded to affect the heatradiated to the fabric. Furthermore, the rate of travel of the fabriccan be varied. For nylon a rate of travel of 20 to 25 yds. per minute isquite satisfactory although the fabric can be run faster by increasingthe length of the heating chamber which means, in the structure shown,increasing the number of heating plates, that is, increasing thedistance over which the fabric is exposed to heat. The heating elementsare located and connected in such fashion that the required additionaltemperature at the sides of the fabric can be produced by any one of anumber of locations at will, and the length of effective heating platesin the direction of travel of the fabric can be changed by turning offentire rows of heaters so that different weights of fabrics can beaccommodated without varying the plate temperatures.

While the controls for the heating elements are described as manuallyoperated, obviously they might be made automatic. Obviously, also, astandard low temperature radiation pyrometer may be used if desired tocontrol the number of plates 32, which are energized and thereby theeffective length of the heating chamber. It will further be understoodthat instead of heating the plates by electric disc heaters, they can beheated by other means, such as vapor or liquid, or by burning fuel gas.In the embodiment shown, the plates are heated by conduction and operateas shields to prevent transmission to the fabric of the higher wavelengths of the heating elements.

Unlike most industrial applications of radiant heat, the a paratus ofthe present invention does not use infra-red lamps, glowing refractorysurfaces, or other small high-temperature heat sources to transmit heatto the fabric, but uses relatively large heating areas operating at lowheat, these areas bein interposed between the heat source and thefabric. As pointed out above, one result of this is that the rate ofheat transfer drops off rapidly as the fabric approaches the temperatureof the plates. This rapid diminution of heat transfer has aself-regulating effect which greatly diminishes the harmful effects ofirregularity in temperature or of hot spots. The transfer of heat fromthe plates is essentially uniform all across the plates, dropping offonly at the edges where it may be maintained .uniformby employingadditional heating elepients or using higher temperatures as described.

As the material being heated approaches the temperature of the plates,the rate of heat transfer drops off at a rapid rate. Therefore, there isvery little tendency for spots of the fabric to overheat. This preventsburning of the seams of the fabric particularly. The air between theplate and the fabric is transparent to radiant heat and is cooler thanthe fabric. The use of the plates permits, moreover, of employing aheating temperature which will generate wave lengths which substantiallycoincide with the highest heat-absorption wave-length band for thematerial being treated.

With the present invention, the surface of heating has to have highemissivity as opposed to high reflectivity. The plates employed may bemade of oxidized iron.

The curtains are made of highly polished aluminum or other reflectingmaterial and are very thin. Since the curtain reflect the radiant energyfrom the plates, the curtains are heated only by convection from theatmosphere in the heat chamber, and, therefore, they block off thetransmission of heat from the plates to the fabric when the curtains areunwound.

While the invention has been described particularly in connection withthe heat treatment of nylon it will be understood that it can be used toset resin-impregnated rayon fabrics and any fabric where temperaturemust be raised to a predetermined level to heat-treat it. Byheattreatment the nylon or other fabric will retain its shape andshrinkage of the fabric in a subsequent dyeing operation will beprevented. If a nylon fabric is not set evenly, the dye will not takeevenly and one part will be darker than another.

Among the advantages of the present method is that the heat transfer isextremely rapid as compared to hot atmosphere heating which means that avery short time of exposure may be employed and, therefore, there isless danger of damage to the fabric. With the process of the presentinvention nylon, for instance, may be heat-treated with the temperatureof the plates approximately 700 F. in about six seconds of exposure. Abetter job of heat treatment can be done due to the rapid penetration ofheat supplied in this manner. The process can be accomplished while thefabric is on a tenterframe conveyor which allows the heat treatment tobe effected while the material is held under tension in. bothdirections. The apparatus is relatively small and compact and less inoverall costs than the elaborate hot atmosphere ovens previouslyrequired. The energy curve of the heat source and the curve of maximumabsorpticn of heat by the fabric substantially coincide. By using aplate as a radiating surface, the plate temperature may be that mostfavorable to absorption of heat by the material being treated.

The method of the present invention not only sets the fabric, reducingresidual shrinkage to a negligible amount but produces a superior handin the fabric, and the characteristic of not retaining wrinkles as aresult of any type of handling is greatly improved.

While the invention has been described in connection with a specificembodiment thereof, it is capable of further modification and thisapplication is intended to cover any variations, uses, or adaptations ofthe invention following, in general, the principles of the invention andincluding such departures from the present disclosure as come withinknown or customary practice in the art to which the invention pertainsand as may be applied to the essential features hereinbefore set forthand as fall within the scope of the invention or the limits of theappended claims.

Having thus described my invention, what I claim is:

l. The method of heat-treating a textile fabric which comprises passingthe fabric between two continuous, uninterrupted, surfaces which arespaced above and below the fabric, while heating said surfaces to causethe surfaces to heat the fabric by radiant heat from said surfaces, thesurfaces being equal in width at least to the width of the fabric andbeing heated to a higher temperature at their edges than in theircenters.

2. A machine for heat-treating textile fabrics comprising a heatingchamber having a pair of parallel, spaced, uninterrupted heatingsurfaces therein which are at least as wide a the fabric which is to betreated, means for conveying the fabric between said surfaces whileholding it under tension both lengthwise and cross-wise, said surfacesbeing disposed to be spaced above and below the fabric as it passesthrough the heating chamber, and means for heating the portions of saidsurfaces, which lie above and below the edges of the fabric to a highertemperature than the portions of the surfaces which register with thecentral portion of the fabric.

3. A machine for heat-treating textile fabrics comprising a heatingchamber having a pair of spaced heating surfaces therein which are atleast as wide as the fabric which is to be treated, means for heatingsaid surfaces, mean for conveying the fabric between the surfaces inspaced relation thereto, and heat-blocking means interposable betweenthe surfaces and the fabric for protecting the fabric from the heat ofthe surfaces.

4. A machine for heat-treating textile fabrics comprising a heatingchamber having a pair of spaced heating surfaces therein, means forheating said surfaces, means for conveying the fabric between thesurfaces in spaced relation thereto, heat-blocking means interposablebetween each surface and the adjacent side of the fabric, means formoving the heat-blocking means to said interposed position, and meansfor interlocking the operations of said last-named means and theconveying means so that, on stoppage of the conveying means, theblocking means is moved to operative position.

5. A machine for heat-treating textile fabrics comprising a heatingchamber having a pair of spaced heating surfaces therein, means forheating said surfaces, means for conveying the fabric between thesurfaces in spaced relation thereto, heat-blocking means interposablebetween each surface and the adjacent side of the fabric, means formoving the heat-blocking means to said interposed position, and meansfor interlocking the operations of said last-named means and theconveying means so that, on stoppage of the conveying means, theblocking means is moved to operative position, and vice versa, onstarting of the conveying means, the blocking means is moved toinoperative position.

6. A machine for heat-treating textile fabrics comprising a heatingchamber having a pair of spaced heating surfaces therein, a tenter-frameconveyor for moving the textile fabric through said heating chamberbetween said surfaces, means for driving said conveyor, a pair ofcurtain rolls journaled at one end of said chamber, heatblockingcurtains wrapped therearound, means for drawing one curtain between eachheating surface and the fabric in the chamber, and means forinterlocking the operations of the last-named means and the drive meansso that on stoppage of the drive means the curtains are drawn betweenthe surfaces and the fabric.

7. A machine for heat-treating textile fabrics comprising a heatingchamber, a plurality of supports mounted in the upper part of saidchamber, a plurality of plates removably secured to said supports, aplurality of supports mounted in the lower part of the chamber, aplurality of plates removably secured to the latter supports inparallelism to the first plates, a tenter-frame conveyor for conveyingthe fabric between the upper and lower plates in spaced relationthereto, said plates extending at least over the full width of thefabric, a plurality of electrical heater secured to the back of eachplate, and means for controlling said heaters.

8. A machine for heat-treating textile fabrics comprising a heatingchamber, means in said chamber for emitting heat, means for conveyingthe fabric, which is to be treated through said chamber, and a pair ofcontinuous, uninterrupted heating plates mounted in the chamber,respectively, to be above and below the fabric being conveyed throughthe chamber and to be spaced from opposite sides of the fabric,respectively, and to be interposed between the opposite sides of thefabric and the heat-emitting means, whereby the plates are heated by theheat-emitting means and the plates, in turn, heat the fabric byradiation.

HENRY E. PECK.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,470,953 Bassler Oct. 16, 19231,613,445 Davis et al Jan. 4, 1927 2,313,173 Schneider Mar. 9, 19432,317,409 Seaton Apr. '27, 1943 2,325,060 Ingersoll July 27, 19432,343,351 Wedler Mar. 7, 1944 2,365,931 Benger Dec. 26, 1944 2,499,141Helmus Feb. 28, 1950 2,524,895 Dodge Oct. 10, 1950 FOREIGN PATENTSNumber Country Date 565,180 Great Britain Oct. 31, 1944

